1. Field of the Invention
The present invention relates to photodiodes which consist of semiconductor compounds.
2. Discussion of Prior Art
It is generally known in the first of optical fiber transmission systems, that multiplex optical signals, that is, signals carried by a plurality of different wavelengths transmitted via an optical fiber, are separated at the terminal of a receiving device into the individual component signals by means of a plurality of optical fibers and that the separated signals are then fed via separate optical fibers to individual photodiodes. Such systems have substantial drawbacks such as the necessity of using a troublesome technique for installing connectors that can obtain low loss contacts between optical fibers and filters and between optical fibers and photodiodes, and further receiving devices are expensive and inconveniently large.